One flight attendant from Hawaii has already purchased her Virgin Galactic ticket with bitcoins, Branson said.

"I hope that it will become more widely accepted," he wrote. "A few years ago many people had doubts about whether Virgin Galactic would ever get off the ground. Now we have gone supersonic, are a long way along the testing process, and are looking forward to launching commercial space flight."

Bitcoin's notoriety soared after the recent arrest of Ross Ulbricht, a 29-year-old from San Francisco who allegedly masterminded the online drug emporium Silk Road. Fans say it is a form of money that is not connected to any nation or government, while critics say it is used often for buying illegal substances online.